Escaflowne meta rambles

A while ago I was going to lay out my Eries head-canon, except to do that I needed to lay out some more general Aston sister head-canon, and in the process of doing that, I got tripped up on the Marlene issue: Specifically, if she was heir, why was she married off to Freid? Wouldn’t it make more sense for her to marry an Asturian citizen (much like Millerna eventually ends up doing with Dryden), and thus, keep her in the country?

( And this is where I get all talky about succession and royal politics in general. )

tl;dr: My head-canon states that Marlene was heir, and Aston married her off to Mahad to form/strengthen an alliance, with the intention that Asturia and Freid would formally unify upon Aston’s death. Except Marlene died first, so that part of the agreement was nulled and voided.